Obsessive-Compulsive Disorder (OCD) is the fourth most prevalent psychiatric disorder with a worldwide lifetime prevalence rate of about 2.5% (Bebbington et al., (1998) Br. J. Psychiatry 173:2-6). In the U.S., OCD affects approximately 3.3 million Americans (National Institutes of Mental Health). For example, in 1990, OCD cost the United States about 8.4 billion in social and economic losses, which accounts for ˜6% of the total mental health costs. OCD typically begins in early childhood or adolescence and can severely affect quality of life. It affects men and women equally. However, onset of OCD is usually earlier in males (between the ages of 6 and 15) than in females (between the ages of 20 and 29). OCD has also been documented in cats and dogs (Overall et al., (2002) J Am Vet Med Assoc. 221(10):1445-52).
In addition to therapeutics, such as serotonin reuptake inhibitors (SRI) or selective serotonin reuptake inhibitors (SSRI), current available treatments for OCD include cognitive psychotherapy (CT) and/or behavioral psychotherapy (BT), either alone or in combination with OCD therapeutics. Acceptance and compliance with CT and/or BT is often difficult and specific methods may need to be matched with specific compulsions or obsessions. Treatment with SRIs and SSRIs alone also may be ineffective in diminishing OCD symptoms. Such a protocol must be closely monitored in subjects, particularly adolescents, for treatment can be associated with negative side effects, such as dizziness, nervousness, insomnia, alterations in blood pressure, sedation, weight gain, irregular heart beats, and nausea. According to Hollander and Wong (Primary Psychiatry, 1995, 2(2): 28-33), 50-60% of OCD patients respond to an initial trial of an SSRI, but this claim is made on the basis of very short trials. According to D. J. Stein, a leading OCD researcher, “there is a paucity of longer-term trials, data on symptom remission and functional improvement, and data on treatment effectiveness in wider clinical practice.” (Stein, J. C. et al., (2007) CNS Spectr. 12(2 Suppl 3): 28-35). Thus, there is a need to develop improved and effective methods for treating obsessive-compulsive disorder.